Formula 1 Race Car Design Takes Finite Element Analysis.pdf

Formula 1 Race Car Design Takes Finite Element
Analysis
To the Next Level
By Dennis Sieminski, P.E.
Formula 1 or Grand Prix racing is
known for its extensive use of advanced
technology, huge monetary investment,
and the attention-grabbing looks of its
highly aerodynamic, open-wheeled race
cars. According to F1 rules, each team
must design and build its own car. This
typically requires an investment
upwards of $1 million for each car and
an annual race team budget that can run
in the $100s of millions. The races are
very technologically demanding because
of the high speeds (cars are capable of +200mph lap speeds), multi-turn paved courses,
and the fact that races are run under all weather conditions in a variety of venues around
the globe. Plus the schedule is intense, with the F1 program typically involving 17 races a
year.
Technology and Talent Provide the Edge
The Minardi Formula 1 Race Team is not the biggest of the Formula 1 racing teams, but
that is exactly what provides the motivation for them to find and exploit technologies that
can neutralize this disadvantage. Since its founding by Gian Carlo Minardi in 1979, the
Minardi Team, based in Faenza, Italy, has imprinted its unique spirit-in-the-face-ofadversity
character on this extremely challenging sport, bringing an instinct for
innovation and eye for talent. One example of Minardi innovation is the introduction of
the titanium gearbox in 2000. In the talent department, Minardi lays claim to grooming a
number of well known drivers, such as Fernando Alonso, who started with them in 2001.
A Search for FEA Simulation Capable of Replacing Prototyping and Testing
In 2004, Minardi began to study how it could improve the structural design of its Formula
1 race cars. An important aspect of this program was determining how they could
enhance the chassis for safety and performance without incurring the massive costs that
prototyping and physical testing in their design process imposed. While Minardi had been
using Finite Element Analysis (FEA) software for many years, the team members felt
they were not getting the full potential from the technology. The team began a six month
test with Noran Engineering’s CAD-independent NEiNastran with the objective of
improving the analysis and simulation results in a way that would significantly reduce the
huge investments they were making in physical prototypes.
The chassis design is quite unique. Paolo Mirabini, Manager of Minardi’s CAE Group,

offers an excellent summary of the multi faceted demands on this component: “The
chassis has to end up with the smoothest and flattest shape possible within the many
engineering constraints which exist. These constraints include desired wheelbase, engine
interface, desired fuel capacity, aerodynamic requirements, and even the driver
dimensions!
To complicate matters, the construction details used in assembling the chassis also affect
its design." That is because the chassis is a
monocoque structure made of high
performance carbon-epoxy composites with
either an aluminum or aramidic honeycomb
core. The fibers within the materials have to
be oriented according to the design, and not
bend, while the ply overlapping and
necessary cuts are minimized. Getting any
of these aspects wrong can affect the
performance of the chassis.
Once a design concept is in place,
modifications and further evolution
continuously interplay with the very
stringent safety requirements for the chassis with the safety regulations becoming the
overriding driving force in the design process.
Physical Testing Validates the Simulations with NEiNastran
There are 15 Impact tests the F1 chassis must survive. Being able to simulate them
correctly in a finite element analysis
environment has the potential to save an
enormous amount of time, money, and
resources in prototyping and testing. In
addition, such a process allows Minardi
engineers to optimize the design and gain
an edge on the race course. Again the
words of Paolo Mirabini offer the best
testament to the demands on the software
simulation: “We tested the 3D model in
NEiNastran with more than 15 impact
tests, including side crash, crash cone
push-off tests and more. The software
surpassed our expectations – and those
expectations are very high.”
Following is a brief description of several of the Impact and Performance Tests to which
Mirabini is referring. These provide a sense of the power, precision, and accuracy that is
required in the engineering analysis software to produce a useful simulation.

Side Crash - This is the most demanding test. A 780Kg cart impacts the side of the
chassis at 10 m/s, and lateral crash appendices (called Crash Cones) are measured, which
include maximum deceleration and maximum force on a cone. Each cone has to take
from 15-35% of the total energy, and no damage can be found on the chassis.
Penetration Test - A square flat plate with the same layout of the chassis in the side area
is quasi-statically penetrated with an aluminum conical impactor until a penetration of
1500 mm is measured. The model must respond to absorbed energy >6000 J, and reaction
load >250kN.
Main Roll Bar Crush - The roll bar is statically pushed with a force of about 120kN via
an inclined plate, impacting the main roll-bar top. Requirements are that deformation is
less than 50mm, and the damaged area must be within 100mm from the load application
plate.
Front Roll Bar Crush - The front roll bar is a reinforcing structure located just behind the
steering wheel. A similar test as in the Main Roll Bar Test is made with a 75kN vertical
force.
Lateral Local Crushes - Several specific locations of the chassis side have to be loaded
with forces varying from 12.5kN to 30 kN. Maximum displacements and no damage
requirements are prescribed.
Torsional Stiffness - Each team has developed its own tradition for desired torsional
stiffness ranging from 15,000 – 40,000 N M/o
Flexural Stiffness - This test is made to check that the rear wall of the chassis is stiff
enough to avoid a "hinge effect" at the interface with the engine, where there is a very
high stiffness change.
All of the tests above were simulated in the NEiNastran analysis environment and most
were able to be replicated very closely. However, there are a few exceptions that require
different handling. For example, the Penetration Test uses a simplified correlated
calculation validated by years of experimental data that was developed within Minardi.
The team used NEiNastran to
simulate these tests, checking static
analysis, buckling and surface
contact. All calculations were
correlated with experimental
measurements. This enabled a
continuous refinement of
methodologies and material data.
During the testing, several
optimization routines were
executed involving modifications

on material choice, layup sequences, local reinforcements, foams, bulkheads, and inserts.
In these optimization exercises, NEiNastran proved flexible enough to manage the
existing model while solving various alternates thrown at it providing highly detailed and
accurate post-processing information. In this way, the effects of the modifications were
able to be well understood by the engineers.
Software Features and Strong Tech Support Make a New Design Process Possible
Minardi worked with Noran Engineering’s Master European Distributor SmartCAE in the
evaluation and implementation of NEiNastran. After the six-month evaluation, the
Minardi team was satisfied that a number of key benefits would be achieved with a
software change. In late 2004, the Minardi Team made the change official and switched
to NEiNastran. Following are several factors the Minardi F1 Team said were instrumental
in their decision to change:
• Faster and better designs. The amount of prototype testing could be reduced
significantly because the accuracy of results using NEiNastran’s Surface Contact feature
was an improvement over the previous method. Similarly, the nonlinear analysis setup
and solution finding also proved far more robust than their former software.
• Fast implementation. An excellent training program combined with timely support from
Noran Engineering allowed the new software system, NEiNastran, NEiAdvanced
Composites and Smart/Browser to be implemented and used by the Minardi team within
a matter of weeks.
• Access and use of legacy data. The system was designed to enable bi-directional access
to legacy and new data without any compatibility issues.
• Reduced 3D modeling time. The creation of the FE model of the chassis was achieved
in about half the time compared to previous software because of the power inherent in the
NEiModeler (FEMAP) Pre and Post Processor which includes the modules NEiAdvanced
Composites and Smart/Browser.
Conclusion
The performance of Minardi’s new cars in the upcoming Formula 1 season will of course
have the attention of its race fans. But other Formula 1 Race Teams will also be looking
with a critical eye. They will want to know whether Minardi’s knack for finding a new
technical edge might be at work again, and if this means they may need to tune up their
FEA software.
Visit the Noran Engineering website to check out other case studies from innovative
companies and learn more about NEiNastran. Information on the Minardi Formula Race
Team can be found at the Minardi FI Team website. See SmartCAE website for
additional information on that product.
Dennis Sieminski is responsible for directing the marketing programs at Noran Engineering and works
with a network of international dealers on customer support and the development of new applications and
business. Mr. Sieminski's academic credentials include engineering and business degrees, as well as a

professional engineer's license. His previous work experience and background in product development in a
range of industries provides him with a hands-on appreciation for the role and benefits of design, analysis,
and simulation software.